Background Carbon monoxide (CO) is a colourless, odourless toxic gas produced during incomplete combustion of carbon-based fuels. Most CO incidents reported to the UK Health Protection Agency (HPA) are due to faulty gas appliances, and legislation exists to ensure gas appliances are properly installed. Methods We present three CO poisoning incidents of unusual origin reported to the HPA. In each, residents living above restaurants were poisoned after workers left charcoal smouldering overnight in specialist or traditional ovens whilst ventilation systems were turned off.